ETC

Question 0

______ such as amobarbital inhibit NAD-linked dehydrogenases by blocking the transfer fromFeS to Q.

Answer 0

Barbiturates

Antimycin A and dimercaprol inhibit the respiratorychain between cytochrome b and cytochrome c. Theclassic poisons H2S, carbon monoxide, and cyanideinhibit cytochrome oxidase and can therefore totally ar-rest respiration. Malonate is a competitive inhibitor ofsuccinate dehydrogenase.
Atractyloside inhibits oxidative phosphorylation byinhibiting the transporter of ADP into and ATP out ofthe mitochondrion

Question 1

______ links the flavoproteins to cytochrome b, the member ofthe cytochrome chain of lowest redox potential.

Answer 1

Ubiquinone or Q (coenzyme Q)

Question 2

The action of _____ is to dissociate oxidationin the respiratory chain from phosphorylation.

Answer 2

Uncouplers

The uncoupler thathas been used most frequently is 2,4-dinitrophenol,but other compounds act in a similar manner. The an-tibiotic oligomycin completely blocks oxidation andphosphorylation by acting on a step in phosphorylation

Question 3

______ postulates that theenergy from oxidation of components in the respiratorychain is coupled to the translocation of hydrogen ions(protons, H+) from the inside to the outside of theinner mitochondrial membrane.

Answer 3

Mitchell’s chemiosmotic theory

Question 4

Respiratory chain complexes that acts as proton pumps:

Answer 4

Complex I, III, IV

Question 5

The electrochemical potential difference is used to drivea membrane-located ATP synthase which in the pres-ence of Pi + ADP forms ATP. What complex is this?

Answer 5

Complex V